During a root canal procedure, the dentist (or, endodontist) typically uses an endodontic file to remove tissue remnants to clean and shape the canal. While working the canal becomes clogged with dentin mud and debris, which interferes with the procedure. Since prior art root canal procedures are almost exclusively carried out using solid drills, the drill must be periodically withdrawn from the canal in order to introduce an antiseptic irrigant solution to flush out unwanted debris. The irrigant solution must to be supplied at relatively high pressure in order to effectively wash the debris out of the canal. Additionally, since the reason for performing a root canal procedure is frequently an infection of the pulp in the root canal and also because of the presence of large numbers of pathogens in the mouth, it is also necessary to thoroughly disinfect the canal, especially before obturation of the canal space and preferably during the course of the entire procedure.
U.S. Pat. No. 4,608,017 discloses a conventional endodontic irrigating instrument for irrigating the root canal of a tooth with an irrigating liquid. The instrument is a hand-piece similar to conventional dental hand-pieces. There is an aspiration needle at the distal end that is designed to insert into a clean or partially cleaned root canal. The instrument is connected directly to the office water and compressed air supplies. Water under pressure can flow through the instrument and out at the distal end in the form of an annular water jet surrounding the aspiration needle. The compressed air flows through a Venturi tube inside the instrument to create a partial vacuum that is used to draw the water and debris out of the canal through the aspiration needle. The flow rate and the pressure of the water and air are controlled manually by regulating valves. When it is desirable to perform irrigation with irrigating solutions such as peroxide solution instead of rinsing water, a container containing such solution may be provided and pressurized by introducing compressed air from a dental unit. The pressurized irrigating solution is then fed by a supply conduit to the head of the instrument.
The endodontic irrigating instrument disclosed in U.S. Pat. No. 4,608,017 is a dedicated device that is separate from the hand-piece used to shape and clean the canal with the endodontic file. In use the dentist must interrupt his work with the file, put it aside, pick up the irrigating instrument, operate it for a period of time, and then put it aside before continuing to work with the file.
U.S. Pat. No. 4,973,247 discloses a typical gas driven dental handpiece assembly. The assembly comprises a supply of compressed gas which operates a turbine for driving a high speed dental cutting or drilling tool. When working with a dental tool of this type a coolant and/or irrigant solution must be provided because of the frictional heat generated and to rinse away debris. The invention described in this patent is an addition to the hand-piece that provides an alternative to using the community water supply as a coolant or propellant fluid in order to provide a sterile working environment. The addition is a cartridge divided by a diaphragm containing coolant liquid on one side of the diaphragm. A mechanism is provided to allow the operator of the hand-piece to controllably divert the turbine drive gas to the empty part of the cartridge. The gas introduced into the cartridge exerts pressure on the diaphragm causing the coolant liquid to move under pressure out of the cartridge and toward the head of the dental tool where it is sprayed onto the work area from an opening located near the connection of the tool to the hand-piece. The sterility concerns are addressed by supplying a new cartridge for each patient.
U.S. Pat. No. 6,527,551 discloses a dental irrigation device aimed at overcoming the drawbacks of prior art systems that are cumbersome, complex and require permanent installations. The invention comprises an irrigant reservoir containing irrigant such as isotonic saline, water or medicaments, mountable on a dental delivery system. Pressurization means such as a standard source of air pressure for pressurizing irrigant is connectable to the reservoir. A handpiece is joined to the reservoir via a supply channel and comprises a standard dental handpiece interface for adapting with dental tools for dispensing irrigant, such as syringe irrigation tips.
The patents described above are typical of the approaches made in the prior art to providing irrigant solution to the site of the dental procedure. None of the prior art irrigant delivery systems of the prior art solve the basic problem of continuously supplying irrigant to the interior of a root canal during the cleaning and shaping phases of a root canal procedure. The problem is not limited to merely supplying the solution but also to supplying it at sufficient pressure to drive out the debris, to maintain the sterility of the surgical environment, and to supply it using a system that is convenient for the operator and as comfortable as possible for the patient.
It is an object of the present invention to provide a dental irrigation device that can be used with a suitable endodontic file to allow continuous flushing of the root canal while the file is inserted into the canal and engaged in cleaning and shaping it.
It is another object of the present invention to provide a dental irrigation device which receives fluid at relatively low pressure and delivers the fluid to the at relatively high pressure to the interior of the canal.
It is an additional object of the present invention to provide an irrigation device that can be retrofitted to existing dental hand pieces.
Additional objects and advantages of the present invention shall become apparent as the description proceeds.